Solar cell module

ABSTRACT

A solar cell module having a solar cell panel with strings of electrically-coupled solar cells arranged in a row includes one or more lead wires that electrically couple the strings and a junction box. The one or more lead wires are arranged such that they do not overlap with each other and such that one or more of the lead wires includes a portion that overlaps and does not electrically connect to interconnector of a string. The lead wires include an interconnector connection part connected to a respective string interconnector, and the interconnector connection parts of the lead wires are arranged in a straight line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/917,815, filed Nov. 2, 2010, now allowed, which claims priority under35 U.S.C. §119(a) to Patent Application No. 10-2010-0045876 filed in theRepublic of Korea on May, 17, 2010, the entire contents of which arehereby incorporated by reference.

BACKGROUND

1. Field

This document relates to a solar cell module having a plurality of solarcells.

2. Related Art

Recently, as the exhaustion of various existing energy resources, suchas oil or coal, is foreseen, an interest in their replacement withalternative energy sources is increasing. Of these alternative energysources, solar cells receive much attention.

A solar cell converts solar energy into electric energy using aphotoelectric transformation effect. One solar cell produces a smallamount of power, usually a few volts. Thus, in order to obtain a greateroutput, a solar cell module can be configured by connecting severalsolar cells in series or in parallel. Waterproofing is used to protectthe solar cells of the module.

In such a solar cell module, conductors (e.g., inter-connectors)connected with positive electrodes and negative electrodes of the solarcells are connected to one or more lead wires to output power generatedby the solar cell module. The lead wires are connected with a junctionbox to output power through a power line of the junction box.

In a solar cell module having such a configuration, the lead wire isdisposed in an additional area outside of an area in which the solarcells are located in a solar cell panel. The additional area, which isrequired for the lead wire, does not contribute to power generation.Thus, the additional portion causes an increase in the size of the solarcell panel and an associated increase in the size of the solar cellmodule.

SUMMARY

In one aspect, there is a solar cell module including a solar cellpanel. The solar cell panel includes an array of solar cells defining aplurality of strings. Each of the plurality of strings includes aplurality of solar cells in electrical connection and arranged in a row.The solar cell module further includes a plurality of interconnectorselectrically connecting the plurality of solar cells of the strings. Thesolar cell module also includes a junction box that receives electriccurrent generated from the plurality of strings. The solar cell moduleincludes a plurality of lead wires electrically coupling the junctionbox to an end portion of the interconnectors. The plurality of leadwires are arranged such that they do not overlap with each other.

Implementations may include one or more of the following features. Forexample, the plurality of strings may include two outer stringspositioned closest to two outer edges of the solar cell panel and one ormore inner strings positioned between the outer strings. Each of theplurality of interconnectors may include an interconnector connectionpart connected to the interconnector of a respective string. Theinterconnector connection parts of the respective lead wires may bearranged in a straight line.

A lead wire of the plurality of lead wires that is connected to theinterconnector of an outer string may include a junction box connectionpart coupled to the junction box and a coupling part coupled to theinterconnector connection part and the junction box connection part. Thejunction box connection part and the interconnector connection part ofthe lead wire of the plurality of lead wires that is connected to theinterconnector of the outer string may be arranged orthogonal to eachother.

The coupling part of the lead wire of the plurality of lead wires thatis connected to the interconnector of the outer string may include afirst coupling part coupled to the interconnector connection part suchthat the first coupling part is orthogonal to and intersects theinterconnector connection part. The coupling part of the lead wire ofthe plurality of lead wires that is connected to the interconnector ofthe outer string may include a second coupling part coupled to the firstcoupling part and the junction box connection part, the second couplingpart being arranged parallel to the interconnector connection part.

The interconnector connection part, the first coupling part, the secondcoupling part, and the junction box connection part of the lead wire ofthe plurality of lead wires that is connected to the interconnector ofthe outer string may be integrally formed.

A lead wire of the plurality of lead wires that is coupled to aninterconnector of an inner string may include a junction box connectionpart coupled to the junction box and the interconnector connection partof the lead wire of the plurality of lead wires that is coupled to theinterconnector of the inner string, such that the junction boxconnection part is orthogonal to the interconnector connection part.

The solar cell module may include an insulating film for insulating theplurality of lead wires from the interconnectors and the solar cells.

At least one of the plurality of interconnectors may be arranged totraverse atop at least one solar cell of the array of solar cells.

In another aspect, there is a lead wire structure installed within asolar cell module. The lead wire structure includes a plurality of leadwires. Each of the plurality of lead wires includes an interconnectorconnection part configured to be connected to an interconnector. Theinterconnector electrically couples a plurality of solar cells of thesolar cell module. Each of the plurality of lead wires also includes ajunction box connection part configured to be connected to a junctionbox of a solar cell module. The plurality of lead wires are arrangedsuch that they do not overlap with each other when connected to theinterconnectors and the junction box.

In another aspect, there is a solar cell module including an array ofsolar cells defining a plane and having a width and length defined byconstituent peripheral cells of the array. The solar cell module furtherincludes a plurality of interconnectors. Each of the plurality ofinterconnectors electrically couples a row of solar cells of the arrayextending in a lengthwise direction. The solar cell module also includesa plurality of leads. Each of the plurality of leads is electricallycoupled to a respective interconnector of the plurality ofinterconnectors. A portion of at least one of the plurality of leadsextends in a widthwise direction and overlaps at least one solar cell ofthe array. The solar cell module also includes a junction box physicallycoupled to each of the plurality of the leads and electrically coupledto each of the plurality of interconnectors through the leads. The solarcell module also includes an insulating layer insulating the pluralityof leads wires from the solar cells and the plurality ofinterconnectors.

Implementations may include one or more of the following features. Forexample, the insulation layer may be positioned between the array ofsolar cells and the plurality of leads.

The insulation layer may be positioned to obscure a view of an entireportion of the plurality of leads traversing in the lengthwise directionwhen viewed from a front side of the solar cell module, the front sidebeing a side upon which light is incident for energy generation.

The solar cell module may include a back sheet that protects a surfaceof the solar cell module opposite a surface upon which light isincident. The plurality of leads may be printed on the back sheet. Theinsulation layer may be opaque.

At least one portion of a lead of the plurality of leads may be locatedbeyond a periphery of the insulating layer. The portion of the lead mayconnect with an interconnector.

According to the foregoing features, because the interconnectorconnection part of the outer lead wire and the interconnector of theinner lead wire are disposed in series, an invalid area can be reducedcompared with a case in which interconnector connection parts aredisposed in parallel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a solar cell module;

FIG. 2 is an exploded perspective view of the solar cell panelillustrated in FIG. 1;

FIG. 3 is a rear view of the solar cell panel illustrated in FIG. 1;

FIG. 4 is an enlarged view of a design of lead wires of the solar cellpanel;

FIG. 5 is a perspective view of a portion of the solar cell illustratedin FIG. 1;

FIG. 6 is an enlarged view of lead wires according to a modification ofFIG. 3;

FIG. 7 is an enlarged view of lead wires according to anothermodification of FIG. 3;

FIG. 8 is a rear view of another solar cell module having lead wires;

FIG. 9 is an enlarged view of another design of lead wires of the solarcell panel; and

FIG. 10 is an enlarged view of lead wires according to a modification ofFIG. 9.

DETAILED DESCRIPTION

Implementations will now be described in detail with reference to thedrawings. In the drawings, the shapes and dimensions may be exaggeratedfor clarity, and the same reference numerals will be used throughout todesignate the same or like components. For clarity, the thicknesses ofthe layers may be enlarged in the drawings. Additionally, when any part,such as a layer, film, area, or plate, is described as being positionedon another part, such description means the part is directly on theother part or above the other part with at least one intermediate orintervening part. On the other hand, if any part is described as beingpositioned directly on another part, such description means that thereis no intermediate or intervening part between the two parts.

FIG. 1 is a front view of a solar cell module, FIG. 2 is an explodedperspective view of the solar cell panel illustrated in FIG. 1, and FIG.3 is a rear view of the solar cell panel illustrated in FIG. 1.

FIG. 4 is an enlarged view of a configuration of lead wires of the solarcell panel, and FIG. 5 is a perspective view of a portion of the solarcell illustrated in FIG. 1.

With reference to FIGS. 1-5, a solar cell module 100 includes a solarcell panel 200. The solar cell panel 200 includes a plurality of solarcells 210, interconnectors 220 that electrically couple the neighboringsolar cells 210, protection layers (e.g., EVA: Ethylene Vinyl Acetate)230 protecting the solar cells 210, a transparent member 240 disposed onthe protection layer 230 on a side of a light receiving surface of thesolar cells 210, and a back sheet 250 made of an opaque material anddisposed at a lower side of the protection layer 230, which is oppositeof the light receiving surface of the solar cells 210.

The solar cell module 100 also includes a frame 300 for receiving thecomponents integrated through a lamination process and a junction box400 for collecting power generated by the solar cells 210.

The back sheet 250 prevents moisture from infiltrating through the rearsurface of the solar cell module 100, thus protecting the solar cells210 against an external environment. The back sheet 250 may have amulti-layered structure that includes a layer for preventing moistureand oxygen infiltration, a layer for preventing chemical corrosion, anda layer having electrical insulating characteristics.

The protection layers 230, when disposed at the upper and lower sides ofthe solar cells 210, are integrated with the solar cells 210 through alamination process. The protection layers 230 serve to prevent corrosionthat can be caused by moisture infiltration and protect the solar cells210 against damage caused by impact forces. The protection layers 230may be made of a polymeric insulating material, such as Ethylene VinylAcetate (EVA).

The transparent member 240 positioned on the protection layer 230 ismade of tempered glass having a high transmittance and excellentanti-damage function. In this case, the tempered glass may be low irontempered glass having a low iron content. An inner surface of thetransparent member 240 may be subjected to an embossing process in orderto enhance a light diffusion effect of the transparent member 240.

As shown in FIG. 5, the solar cells 210 of the solar cell panel 200include a substrate 211 and an emitter part 212 positioned on a lightreceiving surface of the substrate 211 onto which light is incident.First electrodes 213 are included on the emitter part 212, and at leastone first collector 214 is included on the emitter part 212. Ananti-reflection layer 215 is included on regions of the emitter part 212where the first electrodes 213 and the first collector 214 are notlocated, and a second electrode 216 and second collectors 217 areincluded on the opposite side of the light receiving surface.

The solar cell 210 may further include a back surface field (BSF) partformed between the second electrode 216 and the substrate 211. The BSFpart is a region, heavily doped with the same conductive type impuritiesas that of the substrate 211, such as a p+ region.

The BSF part serves as a potential barrier at the back surface of thesubstrate 211. Thus, the phenomenon by which electrons and holesre-combine and become extinct at the back surface of the substrate 211can be reduced, and thus, the efficiency of the solar cells 210 can beimproved.

The substrate 211 is a semiconductor substrate made of silicon of afirst conductive type, (e.g., p-type conductive type silicon). In thiscase, the silicon may be, for example, monocrystalline silicon,polycrystalline silicon, or amorphous silicon. When the substrate 211has a p-type conductive type, it may contain impurities of a trivalentelement such as boron (B), gallium (Ga), indium (In), or the like.

The substrate 211 is processed in order to make the surface of thesubstrate 211 a textured surface. Because the surface of the substrate211 is texturized, a light reflectivity at the light receiving surfaceof the substrate 211 can be reduced. Moreover, the textured surface ofthe substrate 211 operates to direct reflected light into the interiorof the solar cells, increasing a light absorption rate. Accordingly, theefficiency of the solar cells can be improved.

The emitter part 212 is an area where second conductive type, which isopposite to the conductive type of the substrate 211 (e.g., n-typeconductive type), impurities are doped. The emitter part 212 forms a p-njunction with the substrate 211. When the emitter part 212 is of then-type conductive type, the emitter part 212 may be formed by dopingimpurities of a group 5 element such as phosphor (P), arsenic (As),antimony (Sb), or the like.

Accordingly, when electrons in the interior of the semiconductor receiveenergy from light incident on the substrate 211, the electrons migratetoward an n-type semiconductor, while holes migrate toward a p-typesemiconductor. Thus, when the substrate 211 is a p-type semiconductorwhile the emitter part 212 is an n-type semiconductor, the separatedholes migrate toward the substrate 211 and the separated electronsmigrate toward the emitter part 212.

Conversely, the substrate 211 may be an n-type conductive type and madeof a semiconductor material other than silicon. When the substrate 211has the n-type conductive type, the substrate 211 may contain impuritiesof a group 5 element such as phosphor (P), arsenic (As), antimony (Sb),and the like.

Because the emitter part 212 forms the p-n function with the substrate211, when the substrate 211 has the n-type conductive type, the emitterpart 212 has a p-type conductive type. In this case, the separatedelectrons transfer toward the substrate 211 and the separated holestransfer toward the emitter part 212.

When the emitter part 212 has the p-type conductive type, the emitterpart 212 may be formed by doping impurities of a trivalent element suchas boron (B), gallium (Ga), indium (In), and the like, on the substrate211.

The anti-reflection layer 215 may be formed of a silicon nitride film(SiNx), a silicon oxide film (SiO2), or the like, and is positioned onthe emitter part 212 of the substrate 211. The anti-reflection layer 215serves to reduce the portion of light incident on the solar cell 210that is reflected and increases selectivity of a particular wavelengthregion, thus enhancing the efficiency of the solar cell 210. Theanti-reflection layer 215 may have a thickness ranging from 70 nm to 80nm, or may be omitted as necessary.

The plurality of first electrodes 213 are positioned on the emitter part212 and electrically coupled to the emitter part 212. The plurality offirst electrodes 213 are positioned in one direction and are separatedfrom each other. The first electrodes 213 collect charge carriers (e.g.,electrons) that have migrated toward the emitter part 212 and conductthe collected electrons to the corresponding first collector 214.

The plurality of first electrodes 213 may be made of at least oneconductive material, and the conductive material may be at least onematerial selected from the group consisting of nickel (Ni), copper (Cu),silver (Ag), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au),and any of their combinations or alloys, or also may be made of anyother conductive metal material.

The plurality of first collectors 214 are positioned on the emitter part212 and are referred to as a bus bar. The first collectors 214 arepositioned to cross the first electrodes 213. Accordingly, the firstelectrodes 213 and the first collectors 214 are disposed to cross eachother on the emitter part 212.

The first collectors 214 may be made of at least one conductive materialand coupled to the emitter part 212 and to the first electrodes 213.Accordingly, the first collectors 214 output carriers, e.g., electrons,conducted by the first electrodes 213 to an external device.

A conductive metal material of the first collectors 214 may be at leastone material selected from the group consisting of nickel (Ni), copper(Cu), silver (Ag), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold(Au), and any combination or alloy of these, or also may be made of anyother conductive metal material. Moreover, the plurality of firstcollectors 214 may contain the same material as that of the firstelectrodes 213, but may also contain a different material.

The first electrodes 213 and the first collectors 214 may be formed bycoating a conductive metal material on the anti-reflection layer 215,patterning the conductive metal material. The conductive metal materialcan then be baked. During this forming process, the first electrodes 213and the first collectors 214 may be electrically coupled to the emitterpart 212 according to a punch-through operation. Alternatively, thefirst electrodes 213 and the first collectors 214 may be formedseparately and/or through different processes.

The second electrode 216 is positioned on the side opposite of the lightreceiving surface of the substrate 211, namely, on the back surface ofthe substrate 211, and collects carriers (e.g., holes) migrating towardthe substrate 211.

The second electrode 216 is made of at least one conductive material.The conductive material may be at least one material selected from thegroup consisting of nickel (Ni), copper (Cu), silver (Ag), tin (Sn),zinc (Zn), indium (In), titanium (Ti), gold (Au), and any of theircombinations or alloys, or also may be made of any other conductivemetal material.

A plurality of second collectors 217 are positioned under the secondelectrode 216 or on the same surface on which the second electrode 216is formed. The second collectors 217 cross the first electrodes 213, andthe second collectors 217 can be parallel to the first collectors 214.

The second collectors 217 are made of at least one conductive materialand are electrically coupled to the second electrode 216. Accordingly,the second collectors 217 output carriers (e.g., holes) conducted fromthe second electrode 216 to an external device or another conductor.

A conductive metal material of the second collectors 217 may be at leastone material selected from the group consisting of nickel (Ni), copper(Cu), silver (Ag), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold(Au), and any of their combinations or alloys, or may be made of anyother conductive metal material.

An electrical connection structure of the solar cell panel will bedescribed in detail with reference to FIGS. 2 to 4. In FIG. 3, spacesbetween the solar cells 210 are magnified for illustrative purposes, butsubstantially, the neighboring solar cells 210 are disposed at certainintervals (e.g., at narrow intervals of 3 mm or smaller), as shown inFIG. 1.

The plurality of solar cells 210 provided in the solar cell panel 200are arranged in the form of a plurality of “strings.” Here, the“strings” refer to a plurality of solar cells arranged in a row andelectrically connected with each other in series. Accordingly, the solarcell module 200 illustrated in FIGS. 1 to 3 has four strings, e.g.,first to fourth strings S1, S2, S3, and S4. As shown, the strings arearranged in a lengthwise direction and are arranged next to adjacentstrings, side-by-side in a widthwise direction. Hereinafter the firstand fourth strings S1 and S4 positioned at the corners of the solar cellpanel 200 will be referred to as outer strings, and the second and thirdstrings S2 and S3 positioned between the outer strings S1 and S4 will bereferred to as inner strings.

The plurality of solar cells 210 arranged at the respective strings S1to S4 are electrically coupled by interconnectors 220. In detail, thefirst collectors (214 in FIG. 5) of one solar cell among the pluralityof solar cells disposed to be adjacent to each other in a verticaldirection within one string (e.g., the first string S1) are electricallycoupled with the second collectors (217 in FIG. 5) of the neighboringsolar cell by interconnectors 220 a.

The interconnectors 220 a positioned at one end portion of the firststring S1 are connected with interconnectors 220 b positioned at one endportion of the second string S2 by interconnectors 222. Similarly,interconnectors 220 c positioned at one end portion of the third stringS3 are connected with the interconnectors 220 d positioned at one endportion of the fourth string S4 by the interconnectors 222.

Lead wires (LW) for transferring power generated from the solar cells210 to the junction box 400 are coupled to the interconnectors 220 a,220 b, 220 c, and 220 d positioned at the other end portions of thestrings S1 to S4.

In the following description, lead wires coupled to the interconnectors220 a and 220 d of the outer strings, namely, the first and fourthstrings S1 and S4, will be referred to as outer lead wires (OLW), andlead wires coupled to the interconnectors 220 b and 220 c of the innerstrings, namely, the second and third strings S2 and S3, will bereferred to as inner lead wires (ILW).

The lead wire coupled to the interconnectors 220 a of the first stringS1 will be referred to as a first outer lead wire OLW1, the lead wirecoupled to the interconnectors 220 d of the fourth string S4 will bereferred to as a second outer lead wire OLW2, the lead wire coupled tothe interconnectors 220 b of the second string S2 will be referred to asa first inner lead wire ILW1, and the lead wire coupled to theinterconnectors 220 c of the third string S3 will be referred to as asecond inner lead wire ILW2.

Of particular note, the first outer lead wire OLW1 and the second outerlead wire OLW2 do not overlap with the first inner lead wire ILW1 andthe second inner lead wire ILW2. Thus, there is no electrical connectionor other interaction or interference between the outer lead wires OLW1and OLW2 and the inner lead wires ILW1 and ILW2.

In more detail and as shown in FIG. 5, the first outer lead wire OLW1includes an interconnector connection part OLW1-1 connected to theinterconnector 220 a, a coupling part OLW1-2 connected to one endportion of the interconnector connection part OLW1-1, and a junction boxconnection part OLW1-3 connected to the other end portion of thecoupling part OLW1-2. Likewise, the second outer lead wire OLW2 includesan interconnector connection part OLW2-1 connected to the interconnector220 d, a coupling part OLW2-2 connected to one end portion of theinterconnector connection part OLW2-1, and a junction box connectionpart OLW2-3 connected to the other end portion of the coupling partOLW2-2.

The first inner lead wire ILW1 includes an interconnector connectionpart ILW1-1 connected to the corresponding interconnector 220 b and ajunction box connection part ILW1-2 connected to one end portion of theinterconnector connection part ILW1-1. Likewise, the second inner leadwire ILW2 includes an interconnector connection part ILW2-1 connected tothe corresponding interconnector 220 c and a junction box connectionpart ILW2-2 connected to one end portion of the interconnectorconnection part ILW2-1.

The interconnector connection part (OLW1-1, OWL-2-1, ILW1-1, and ILW2-1)of each lead wire connected to the interconnectors (2201, 220 b, 220 c,and 220 d) is also called a “bus (bar) ribbon” or a “bus (bar)interconnector”.

The interconnector connection parts OLW1-1 and OLW2-1 of the first andsecond outer lead wires OLW1 and OLW2 are arranged to cross thecorresponding interconnectors 220 a and 220 d, respectively, and thejunction box connection parts OLW1-3 and OLW2-3 are arranged to crossthe interconnector connection parts OLW1-1 and OLW2-1, namely, arrangedto be parallel to the interconnectors 220 a and 220 d, respectively.

Likewise, the interconnector connection parts ILW1-1 and ILW2-1 of thefirst and second inner lead wires ILW1 and ILW2 are arranged to crossthe corresponding interconnectors 220 b and 220 c, respectively, and thejunction box connection parts ILW1-2 and ILW2-2 are arranged to crossthe interconnector connection parts ILW1-1 and ILW2-1, respectively.

Additionally, the interconnector connection part OLW1-1 of the firstouter lead wire OLW1 is arranged in a generally straight line with theinterconnector connection part ILW1-1 of the first inner lead wire ILW1.Likewise, the interconnector connection part ILW2-1 of the second innerlead wire ILW2 is arranged in a straight line with the interconnectorconnection part OLW2-1 of the second outer lead wire OLW2.

The interconnector connection part OLW1-1 of the first outer lead wireOLW1, the interconnector connection part ILW1-1 of the first inner leadwire ILW1, the interconnector connection part ILW2-1 of the second innerlead wire ILW2, and the interconnector connection part OLW2-1 of thesecond outer lead wire OLW2 are generally arranged in a straight lineoverall.

According to such characteristics, because the interconnector connectionpart OLW1-1 of the first outer lead wire OLW1 and the interconnectorconnection part OLW2-1 of the second outer lead wire OLW2 are disposedin a straight line with the interconnection connection part ILW1-1 ofthe first inner lead wire ILW1 and the interconnector connection partILW2-1 of the second inner lead wire ILW2, a portion or region of thesolar cell panel 200 that is not used for producing energy, i.e., aportion in which the lead wires LW are disposed, can be reduced comparedto the related art in which the interconnector connection parts aredisposed beside each other.

The coupling part OLW1-2 coupling the interconnector connection partOLW1-1 of the first outer lead wire OLW1 and the junction box connectionpart OLW1-3 includes a first coupling part OLW1-2-1 coupled to an endportion of the interconnector connection part OLW1-1 such that itcrosses the interconnector connection part OLW1-1 and a second couplingpart OLW1-2-2 coupled to the first coupling part OLW1-2-1 and thejunction box connection part OLW1-3 such that it is parallel to theinterconnector connection part OLW1-1. With such a configuration, thefirst outer lead wire OLW1 is arranged in a stepwise manner.

Particularly, in the stepwise arrangement, an end portion of theinterconnector connection part OLW1-1 of the first outer lead wire OLW1is positioned under an end portion of the first coupling part OLW1-2-1,and an end portion of the junction box connection part OLW1-3 ispositioned under an end portion of the second coupling part OLW1-2-2. Insome implementations, one or more of the interconnector connection partOLW1-1 of the first outer lead wire OLW1, the first coupling partOLW1-2-1, the second coupling part OLW1-2-2 and the junction boxconnection part OLW1-3 can be formed as a unitary member and theportions thereof corresponding to such parts can be formed by bends,joints, or other transitions of the unitary member.

Likewise, the coupling part OLW2-2 coupling the interconnectorconnection part OLW2-1 of the second outer lead wire OLW2 and thejunction box connection part OLW2-3 includes a first coupling partOLW2-2-1 coupled to an end portion of the interconnector connection partOLW2-1 such that it crosses the interconnector connection part OLW2-1and a second coupling part OLW2-2-2 coupled to the first coupling partOLW2-2-1 and the junction box connection part OLW2-3 such that it isparallel to the interconnector connection part OLW2-1. With such aconfiguration, the second outer lead wire OLW2 is arranged in a stepwisemanner.

In this arrangement, an end portion of the interconnector connectionpart OLW2-1 of the second outer lead wire OLW2 is positioned under anend portion of the first coupling part OLW2-2-1, and an end portion ofthe junction box connection part OLW2-3 is positioned under an endportion of the second coupling part OLW2-2-2. In some implementations,one or more of the interconnector connection part OLW2-1 of the secondouter lead wire OLW2, the first coupling part OLW2-2-1, the secondcoupling part OLW2-2-2 and the junction box connection part OLW2-3 canbe formed as a unitary member and the portions thereof corresponding tosuch parts can be formed by bends, joints, or other transitions of theunitary member.

With respect to the inner lead wires ILW1 and ILW2, the interconnectorconnection parts ILW1-1 and ILW2-1 are positioned under the junction boxconnection parts ILW1-2 and ILW2-2.

With such an arrangement of the lead wires LW, although the lead wiresare divided into several sections, steps required for producing thesolar cell panel 200 can be reduced.

According to the foregoing structure, the first outer lead wire OLW1does not overlap with the first inner lead wire ILW1, and the secondouter lead wire OLW2 does not overlap with the second inner lead wireILW2. Also, there is no connection between the outer lead wires OLW1 andOLW2 and the inner lead wires ILW1 and ILW2 that would interfere withconduction of charge carriers within each of the lead wires.Additionally, because the lead wires do not overlap, there is no need toinclude an insulating film between the outer lead wires OLW1 and OLW2and the inner lead wires ILW1 and ILW2.

In the design described by the related art, in which the interconnectorconnection parts OLW1-1 and OLW2-1 of the outer lead wires OLW1 and OLW2and the interconnector connection parts ILW1-1 and ILW2-1 of the innerlead wires ILW1 and ILW2 are disposed beside each other, an insulatingfilm would need to be disposed between the outer lead wires OLW1 andOLW2 and the inner lead wires ILW1 and ILW2 in order to prevent thecoupling parts OLW1-2 and OLW2-2 of the outer lead wires OLW1 and OLW2from contacting the interconnector connection parts ILW1-1 and ILW2-1 ofthe inner lead wires ILW1 and ILW2 at an overlapping portion.

Thus, when the interconnector connection parts OLW1-1 and OLW2-1 of theouter lead wires OLW1 and OLW2 and the interconnector connection partsILW1-1 and ILW2-1 of the inner lead wires ILW1 and ILW2 are arranged ina generally straight line and the outer lead wires OLW1 and OLW2 arearranged in the stepwise configuration, there is no need to include aninsulating film or other electrical insulating material for insulatingthe outer lead wires OLW1 and OLW2 and the inner lead wires ILW1 andILW2 from one another, so the manufacturing cost and the number ofmanufacturing processes for the solar cell panel 200 can be reduced.

Meanwhile, an insulating film 260 used to insulate the outer lead wiresOLW1 and OLW2 and the inner lead wires ILW1 and ILW2 from the solarcells 210 and the interconnectors is formed to have a size sufficientfor covering the entirety of the coupling parts OLW1-2 and OLW2-2 of theouter lead wires OLW1 and OLW2, a portion of the junction box connectionparts OLW1-3 and OLW2-3, and a portion of the junction box connectionparts ILW1-2 and ILW2-2 of the inner lead wires ILW1 and ILW2. Theinsulating film 260 is positioned on the rear surface of the solar cell210 and in the spaces between the lead wires OLW1, OLW2, ILW1 and ILW2.

In this case, the insulating film 260 is made of an opaque materialwhich is similar to or the same as that of the back sheet 250. Becausethe material of the insulating film 260 is opaque, only theinterconnector connection parts OLW1-1, OLW2-1, ILW1-1, and ILW2-1 ofthe lead wires OLW1, OLW2, ILW1, and ILW2 are seen at the back side ofthe solar cell module 100, so the external appearance and insulationcharacteristics can be improved. Additionally, because the lead wires donot extend beyond the interconnector connection parts OLW1-1, OLW-2-1,ILW-1-1, and ILW-2-1, only the interconnector connection parts OLW1-1,OLW2-1, ILW1-1, and ILW2-1 of the lead wires OLW1, OLW2, ILW1, and ILW2are seen at the front back side of the solar cell module 100.

In the foregoing examples, the interconnector connection parts OLW1-1and OLW2-1, the first coupling parts OLW1-2-1 and OLW2-2-1, the secondcoupling parts OLW1-2-2 and OLW2-2-2, and the junction box connectionparts OLW1-3 and OLW2-3 of the outer lead wires OLW1 and OLW2 aredescribed as being divided (i.e., separate wires). Likewise, theinterconnector connection parts ILW1-1 and ILW2-1 and the junction boxconnection parts ILW1-2 and ILW2-2 of the inner lead wires ILW1 and ILW2are described as being divided (i.e., separate wires).

However, the design of solar cell module 100 is not limited thereto andthe lead wires OLW1, OLW2, ILW1, and ILW2 may be integrally formed.

Such a design of the lead wires will now be described with reference toFIG. 6, which is an enlarged view of lead wires according to amodification of the lead wires of FIG. 3. As illustrated, the outer leadwires OLW1 and OLW2 are each configured as a single body, respectively,and each body includes interconnector connection parts OWL1-1 andOLW2-2, first coupling parts OLW1-2-1 and OLW2-2-1, second couplingparts OLW1-2-2 and OLW2-2-2, and junction box connection parts OLW1-3and OLW2-3. Likewise, the inner lead wires ILW1 and ILW2 are eachconfigured as a single body, respectively, and each body includesinterconnector connection parts ILW1-1 and ILW2-1 and junction boxconnection parts ILW1-2 and ILW2-2.

The outer lead wires OLW1 and OLW2 and the inner lead wires ILW1 andILW2 may be configured as a single body, respectively. Alternatively,although not shown, at least one of the interconnector connection partsOLW1-1 and OLW2-1, the first coupling parts OLW1-2-1 and OLW2-2-1, thesecond coupling parts OLW1-2-2 and OLW2-2-2, and the junction boxconnection parts OLW1-3 and OLW2-3 of the outer lead wires OLW1 and OLW2may be formed as a separate member from the other parts.

Additionally, the lead wires may be configured to have a form differentfrom those of the embodiments illustrated in FIGS. 3 and 6. This willnow be described with reference to FIG. 7. FIG. 7 is an enlarged view oflead wires according to another modification of the lead wires of FIG.3. As illustrated, the modification illustrated in FIG. 7 may be usedwhen connection parts of the junction box 400 (shown in FIGS. 1 and 3)are disposed in a direction of the strings of the solar cell panel 200,which is different in the structure of the lead wires from those of theimplementations described above, which are used when the connectionparts of the junction box connected to the lead wires are disposed in adirection across the strings of the solar cell panel.

In detail, with regard to FIG. 7, the junction box connection partsOLW1-3 and OLW2-3 and the interconnector connection parts OLW1-1 andOLW2-1 of the outer lead wires OLW1 and OLW2 are arranged to be parallelsuch that they cross the interconnectors, and the coupling parts OLW1-2and OLW2-2 coupling the interconnector connection parts OLW1-1 andOLW2-1 and the junction box connection parts OLW1-3 and OLW2-3 arelinearly formed to be arranged to be parallel to the interconnectors.

The junction box connection parts ILW1-2 and ILW2-2 and theinterconnector connection parts ILW1-1 and ILW2-1 of the inner leadwires ILW1 and ILW2 are arranged to be parallel to each other such thatthey cross the interconnectors, and the coupling parts ILW1-3 and ILW2-3coupling the interconnector connection parts ILW1-1 and ILW2-1 and thejunction box connection parts ILW1-2 and ILW2-2 are arranged to beparallel to the interconnectors.

As shown in FIG. 7, a length L1 of the coupling part ILW1-3 of the firstinner lead wire ILW1 and a length L2 of the coupling part ILW2-3 of thesecond inner lead wire ILW2 in direction of the strings may bedifferent, and also a length L3 of the coupling part OLW1-2 of the firstouter lead wire OLW1 and a length L4 of the coupling part OLW2-2 of thesecond outer lead wire OLW2 in the direction of the strings may bedifferent.

In FIG. 7, it is illustrated such that the length L1 of the couplingpart ILW1-3 of the first inner lead wire ILW1 and the length L3 of thecoupling part OLW1-2 of the first outer lead wire OLW1 are shorter thanthe length L2 of the coupling part ILW2-3 of the second inner lead wireILW2 and the length L4 of the coupling part OLW2-2 of the second outerlead wire OLW2. However, the length L1 of the coupling part ILW1-3 ofthe first inner lead wire ILW1 and the length L3 of the coupling partOLW1-2 of the first outer lead wire OLW1 may be longer than the lengthL2 of the coupling part ILW2-3 of the second inner lead wire ILW2 andthe length L4 of the coupling part OLW2-2 of the second outer lead wireOLW2.

As for the lead wires having such configurations, similar to theimplementations described above, at least one of the parts may be formedto be separated from the other parts or all of the parts may beintegrally formed as a single body.

FIG. 8 is a rear view of a solar cell module having lead wires accordingto another implementation of a solar cell module. A solar cell moduleaccording to the implementation of FIG. 8 includes six strings, namely,first to sixth strings S1, S2, S3, S4, S5, and S6. Thus, the first andsixth strings S1 and S6 are outer strings, and the second to fifthstrings S2, S3, S4, and S5 are inner strings.

The lead wires used for the solar cell module having the configurationof FIG. 8 are configured to have an overall shape and structure similarto those of the lead wires according to the implementation of FIGS. 3,4, and 6, and are different in that the interconnector connection partILW1-1 of the first inner lead wire ILW1 is formed having a lengthsufficient to connect with both the interconnector 220 b of the secondstring S2 and the interconnector 220 c of the third string S3. Likewise,the interconnector connection part ILW2-1 of the second inner lead wireILW2 is formed having a length sufficient to connect with both theinterconnectors 220 d and 220 e of the fourth and fifth strings S4 andS5. Reference numerals OLW1-1 and OLW2-1 in FIG. 8 denote interconnectorconnection parts of the first and second outer lead wires OLW1 and OLW2,respectively.

In some implementations, the solar cell module can include other numbersof strings of solar cells. For example, the solar cell module caninclude first to eighth strings. The first and eighth strings constituteouter strings, while the other remaining strings, namely the second toseventh strings constitute inner strings. Accordingly, and asillustrated in FIGS. 9 and 10, in a solar cell module that includeseight strings, the lead wires may include a first outer lead wire OLW1connected with interconnectors of the first string, a first inner leadwire ILW1 simultaneously connected with interconnectors of the secondand third strings, a second inner lead wire ILW2 connected withinterconnectors of the fourth string, a third inner lead wire ILW3connected with interconnectors of the fifth string, a fourth inner leadwire ILW4 connected with interconnectors of the sixth and seventhstrings, and a second outer lead wire OLW2 connected withinterconnectors of the eighth string.

The first outer lead wire OLW1 connected with the interconnectors of thefirst string, and the second outer lead wire OLW2 connected with theinterconnectors of the eighth string may be formed to have the samestructure as that of the first inner lead wire ILW1 simultaneouslyconnecting the interconnectors of the second and third strings and thefourth inner lead wire ILW4 simultaneously connecting theinterconnectors of the sixth and seventh strings as shown in FIG. 9, ormay be formed to have such a structure as illustrated in FIG. 10.

In this manner, the lead wires may be arranged in one of a number ofvarious different configurations such that they do not overlap with eachother. Thus, the need for an insulating material to be included betweenoverlapping portions of the lead wires can be avoided. As also describedabove, the configuration of the lead wires can be selected such that thelead wires do not extend beyond the interconnector connecting parts.

Although to the foregoing disclosure includes a number of illustrativeimplementations, it should be understood that numerous othermodifications and variations are possible that will fall within thescope of the principles of this disclosure. More particularly,variations and modifications are possible in the number of componentparts, the materials thereof, the manner of producing and/or assemblingthe component parts, and/or the arrangements of the component parts.

What is claimed is:
 1. A solar cell module comprising: a solar cellpanel including two outer strings and one or more inner stringspositioned between the outer strings; a plurality of interconnectorselectrically connecting the plurality of solar cells of the strings; aplurality of lead wires electrically coupling a junction box to theinterconnectors; and an insulating layer insulating the plurality oflead wires from the solar cells and the plurality of interconnectors,wherein the plurality of lead wires are arranged such that they do notoverlap with each other, wherein two outer lead wires that is connectedto the interconnector of a respective outer string include aninterconnector connection part connected to the interconnector of arespective outer string and a first coupling part coupled to theinterconnector connection part, wherein a width of the insulating layeris equal to or larger than a distance between the first coupling partsof the two outer lead wires.
 2. The solar cell module of claim 1,wherein the plurality of lead wires further include one or more innerlead wires that is connected to the interconnector of a respective innerstring, wherein the inner lead wire includes an interconnectorconnection part that is connected to the interconnector of a respectiveinner string, wherein the interconnector connection parts of therespective lead wires are arranged in a straight line.
 3. The solar cellmodule of claim 2, wherein the outer lead wire further includes a secondcoupling part coupled to the first coupling part and a junction boxconnection part coupled to the second coupling part.
 4. The solar cellmodule of claim 3, wherein the interconnector connection part and thesecond coupling part of the outer lead wire are arranged parallel toeach other, and the first coupling part and the junction box connectionpart of the outer lead wire are arranged orthogonal to theinterconnector connection part and the second coupling part of the outerlead wire.
 5. The solar cell module of claim 3, wherein a length of theinsulating layer is equal to or larger than a distance between thejunction box connection part and the interconnector connection part ofthe outer lead wire.
 6. The solar cell module of claim 3, wherein theinterconnector connection part, the first coupling part, the secondcoupling part and the junction box connection part of the outer leadwire are integrally formed.
 7. The solar cell module of claim 3, whereinat least one of the interconnector connection part, the first couplingpart, the second coupling part and the junction box connection part ofthe outer lead wire are formed to be separated from the other parts. 8.The solar cell module of claim 7, wherein an end portion of theinterconnector connection part of the outer lead wire is positioned at alower side of an end portion of the first coupling part, and an endportion of the junction box connection part is positioned at a lowerside of an end portion of the second coupling part.
 9. The solar cellmodule of claim 2, wherein the outer lead wire further includes ajunction box connection part coupled to the first coupling part.
 10. Thesolar cell module of claim 9, wherein the interconnector connection partand the junction box connection part of the outer lead wire are arrangedparallel to each other and the first coupling part of the outer leadwire is arranged orthogonal to the interconnector connection part andthe junction box connection part of the outer lead wire.
 11. The solarcell module of claim 9, wherein the interconnector connection part, thefirst coupling part and the junction box connection part of the outerlead wire are integrally formed.
 12. The solar cell module of claim 9,wherein at least one of the interconnector connection part, the firstcoupling part and the junction box connection part of the outer leadwire are formed to be separated from the other parts.
 13. The solar cellmodule of claim 12, wherein an end portion of the interconnectorconnection part of the outer lead wire is positioned at a lower side ofone end portion of the first coupling part, and an end portion of thejunction box connection part is positioned at a lower side of anotherend portion of the first coupling part.
 14. The solar cell module ofclaim 2, wherein the inner lead wire further includes a junction boxconnection part being coupled to the interconnector connection part thatis connected to the interconnector of the inner string.
 15. The solarcell module of claim 14, wherein the interconnector connection part andthe junction box connection part of the inner lead wire are integrallyformed.
 16. The solar cell module of claim 14, wherein theinterconnector connection part and the junction box connection part ofthe inner lead wire are formed to be separated from each other, and anend portion of the interconnector connection part of the inner lead wireis positioned at a lower side of an end portion of the junction boxconnection part of the inner lead wire.
 17. The solar cell module ofclaim 2, wherein the inner lead wire further includes a third couplingpart being coupled to the interconnector connection part of the innerstring and a junction box connection part being coupled to the thirdcoupling part, the third coupling part being arranged orthogonal to theinterconnector connection part of the inner string and the junction boxconnection part being arranged orthogonal to the third coupling part.18. The solar cell module of claim 17, wherein the interconnectorconnection part, the third coupling part and the junction box connectionpart of the inner lead wire are integrally formed.
 19. The solar cellmodule of claim 17, wherein at least one of the interconnectorconnection part, the third coupling part and the junction box connectionpart of the inner lead wire are formed to be separated from the otherparts.
 20. The solar cell module of claim 19, wherein an end portion ofthe interconnector connection part of the inner lead wire is positionedat a lower side of one end portion of the third coupling part, and anend portion of the junction box connection part is positioned at a lowerside of another end portion of the third coupling part.